<?php
namespace Dwoo\Plugins\Blocks;
use Dwoo\Block\Plugin;
use Dwoo\Compiler;
use Dwoo\ICompilable\Block;
use Dwoo\IElseable;

/**
 * Loops over an array and moves the scope into each value, allowing for shorter loop constructs
 *
 * Note that to access the array key within a loop block, you have to use the {$_key} variable,
 * you can not specify it yourself.
 * <pre>
 *  * from : the array that you want to iterate over
 *  * name : loop name to access it's iterator variables through {$.loop.name.var} see {@link http://wiki.dwoo.org/index.php/IteratorVariables} for details
 * </pre>
 * Example :
 *
 * instead of a foreach block such as :
 *
 * <code>
 * {foreach $variable value}
 *   {$value.foo} {$value.bar}
 * {/foreach}
 * </code>
 *
 * you can do :
 *
 * <code>
 * {loop $variable}
 *   {$foo} {$bar}
 * {/loop}
 * </code>
 *
 * This software is provided 'as-is', without any express or implied warranty.
 * In no event will the authors be held liable for any damages arising from the use of this software.
 *
 * @author     Jordi Boggiano <j.boggiano@seld.be>
 * @copyright  Copyright (c) 2008, Jordi Boggiano
 * @license    http://dwoo.org/LICENSE   Modified BSD License
 * @link       http://dwoo.org/
 * @version    2.0
 * @date       2013-09-06
 * @package    Dwoo
 */
class BlockLoop extends Plugin implements Block, IElseable {
	public static $cnt = 0;

	public function begin($from, $name = 'default') {

	}

	public static function preProcessing(Compiler $compiler, array $params, $prepend, $append, $type) {
		// get block params and save the current template pointer to use it in the postProcessing method
		$currentBlock                         =& $compiler->getCurrentBlock();
		$currentBlock['params']['tplPointer'] = $compiler->getPointer();

		return '';
	}

	public static function postProcessing(Compiler $compiler, array $params, $prepend, $append, $content) {
		$params = $compiler->getCompiledParams($params);
		$tpl    = $compiler->getTemplateSource($params['tplPointer']);

		// assigns params
		$src  = $params['from'];
		$name = $params['name'];

		// evaluates which global variables have to be computed
		$varName       = '$dwoo.loop.' . trim($name, '"\'') . '.';
		$shortVarName  = '$.loop.' . trim($name, '"\'') . '.';
		$usesAny       = strpos($tpl, $varName) !== false || strpos($tpl, $shortVarName) !== false;
		$usesFirst     = strpos($tpl, $varName . 'first') !== false || strpos($tpl, $shortVarName . 'first') !== false;
		$usesLast      = strpos($tpl, $varName . 'last') !== false || strpos($tpl, $shortVarName . 'last') !== false;
		$usesIndex     = $usesFirst || strpos($tpl, $varName . 'index') !== false || strpos($tpl, $shortVarName . 'index') !== false;
		$usesIteration = $usesLast || strpos($tpl, $varName . 'iteration') !== false || strpos($tpl, $shortVarName . 'iteration') !== false;
		$usesShow      = strpos($tpl, $varName . 'show') !== false || strpos($tpl, $shortVarName . 'show') !== false;
		$usesTotal     = $usesLast || strpos($tpl, $varName . 'total') !== false || strpos($tpl, $shortVarName . 'total') !== false;

		if (strpos($name, '$this->scope[') !== false) {
			$usesAny = $usesFirst = $usesLast = $usesIndex = $usesIteration = $usesShow = $usesTotal = true;
		}

		// gets foreach id
		$cnt = self::$cnt++;

		// builds pre processing output
		$pre = Compiler::PHP_OPEN . "\n" . '$_loop' . $cnt . '_data = ' . $src . ';';
		// adds foreach properties
		if ($usesAny) {
			$pre .= "\n" . '$this->globals["loop"][' . $name . '] = array' . "\n(";
			if ($usesIndex) {
				$pre .= "\n\t" . '"index"		=> 0,';
			}
			if ($usesIteration)
				$pre .= "\n\t" . '"iteration"		=> 1,';
			if ($usesFirst)
				$pre .= "\n\t" . '"first"		=> null,';
			if ($usesLast)
				$pre .= "\n\t" . '"last"		=> null,';
			if ($usesShow)
				$pre .= "\n\t" . '"show"		=> $this->isTraversable($_loop' . $cnt . '_data, true),';
			if ($usesTotal)
				$pre .= "\n\t" . '"total"		=> $this->count($_loop' . $cnt . '_data),';
			$pre .= "\n);\n" . '$_loop' . $cnt . '_glob =& $this->globals["loop"][' . $name . '];';
		}
		// checks if the loop must be looped
		$pre .= "\n" . 'if ($this->isTraversable($_loop' . $cnt . '_data' . (isset($params['hasElse']) ? ', true' : '') . ') == true)' . "\n{";
		// iterates over keys
		$pre .= "\n\t" . 'foreach ($_loop' . $cnt . '_data as $tmp_key => $this->scope["-loop-"])' . "\n\t{";
		// updates properties
		if ($usesFirst) {
			$pre .= "\n\t\t" . '$_loop' . $cnt . '_glob["first"] = (string) ($_loop' . $cnt . '_glob["index"] === 0);';
		}
		if ($usesLast) {
			$pre .= "\n\t\t" . '$_loop' . $cnt . '_glob["last"] = (string) ($_loop' . $cnt . '_glob["iteration"] === $_loop' . $cnt . '_glob["total"]);';
		}
		$pre .= "\n\t\t" . '$_loop' . $cnt . '_scope = $this->setScope(array("-loop-"));' . "\n/* -- loop start output */\n" . Compiler::PHP_CLOSE;

		// build post processing output and cache it
		$post = Compiler::PHP_OPEN . "\n" . '/* -- loop end output */' . "\n\t\t" . '$this->setScope($_loop' . $cnt . '_scope, true);';
		// update properties
		if ($usesIndex) {
			$post .= "\n\t\t" . '$_loop' . $cnt . '_glob["index"]+=1;';
		}
		if ($usesIteration) {
			$post .= "\n\t\t" . '$_loop' . $cnt . '_glob["iteration"]+=1;';
		}
		// end loop
		$post .= "\n\t}\n}\n" . Compiler::PHP_CLOSE;
		if (isset($params['hasElse'])) {
			$post .= $params['hasElse'];
		}

		return $pre . $content . $post;
	}
}